Projects / Programmes source: ARIS

Assesment of natural and antropogenic processes in micrometeorology of Postojna cave system by numerical models and modern methods of data aquisition and transfer

Research activity

Code Science Field Subfield
2.05.00  Engineering sciences and technologies  Mechanics   

Code Science Field
P170  Natural sciences and mathematics  Computer science, numerical analysis, systems, control 

Code Science Field
2.03  Engineering and Technology  Mechanical engineering 
cave climate, natural ventilation, numerical model, Delay Tolerant Networks (DTN), automatic data aquisition system
Evaluation (rules)
source: COBISS
Researchers (10)
no. Code Name and surname Research area Role Period No. of publicationsNo. of publications
1.  11773  PhD Marija Zlata Božnar  Physics  Researcher  2014 - 2017  269 
2.  17549  Franjo Drole    Technical associate  2014 - 2017  105 
3.  16180  PhD Franci Gabrovšek  Mechanics  Head  2014 - 2017  450 
4.  27664  PhD Boštjan Grašič  Physics  Researcher  2014 - 2017  173 
5.  09652  PhD Andrej Mihevc  Geography  Researcher  2014 - 2017  793 
6.  04290  PhD Primož Mlakar  Physics  Researcher  2014 - 2017  266 
7.  20220  PhD Janez Mulec  Biology  Researcher  2014 - 2017  479 
8.  12605  PhD Metka Petrič  Geology  Researcher  2014 - 2017  524 
9.  08099  PhD Tadej Slabe  Geography  Researcher  2014 - 2017  682 
10.  10443  PhD Stanka Šebela  Geology  Researcher  2014 - 2017  520 
Organisations (2)
no. Code Research organisation City Registration number No. of publicationsNo. of publications
1.  0618  Research Centre of the Slovenian Academy of Sciences and Arts  Ljubljana  5105498000  61,885 
2.  2574  MEIS environmental cosulting d.o.o.  Šmarje - Sap  2271478  302 
Postojna cave is one of the World's most prominent show caves, visited by over 500,000 tourists a year, 90 % of them from the abroad. Sustainable management is a big challenge in show caves. While direct physical impact of the touristic infrastructure on cave environment can be relatively easily assessed, the assessment of indirect impacts of tourism is a difficult task. Tourism is changing the cave climate, which has a fundamental role in many natural processes in cave and is a crucial factor of the cave ecosystem. Despite the growing interest in cave climate, most of the reports are limited to phenomenological level. However, an in-depth understanding of cave microclimate and assessment of potential impact of tourism, can only be based on good numerical models, verified and validated by modern monitoring system. The modelling will be done on two levels. Basic models in simple geometries will be developed and applied to explore interaction between the outside and cave atmosphere. These models will help us understanding  the physics behind the more complex cave climate model of Postojna cave. Microclimatic model of Postojna cave system will be based upon Ventsim Visual, which is basically a mine ventilation modelling environment, but contains all the necessary physics for simulating natural ventilation in caves: atmospheric thermodynamics, compressible flow in confined spaces, heat exchange between atmosphere and surrounding rock strata, advective transport of gasses and dust. Sources of heat, moisture, gasses and dust are inherent part of the model. The modelling domain will be based on a new 3D digital model of Postojna cave system with surface topography and distribution of entrances. The complex geometry of cave system, and the fact that all cave maps are insufficient, presents a big challenge in model development. Time dependent boundary conditions of an outside atmosphere will be monitored, and forecasted by MEIS group with the WRF meteorological model in high locally spatial resolution. The model verification and validation will be based on monitoring of the atmospheric parameters within the cave. Temperatures, wind velocities and CO2 concentration have been monitored at four stations in the cave since 2010. The data transfer from the stations to the data server will be realised via DTN (Delay-Tolerant-Network), which will be developed and used in the specific environment of the cave. The first experimental data transfer via DTN in the cave was done in the previous project. The recently published report on that drew attention of the international DTN scene; it also received praise from Vint Cerf, one of the "fathers" of the internet and DTN technology. Several measurement campaigns are planned, with extended network of observation points, during typical and most dynamic micrometeorological periods.   The final result of the project will be a working microclimatic model of Postojna cave and autonomous growing data base of microclimatic measurements. The model will serve as a base for the analysis and forecast of potential impact of present and future activities related to tourism in the cave. The complete system will serve a raw model and will be presented to the managers of other tourist caves around the world. The model will enable better understanding of cave climate in general. It will resolve  values of temperature, CO2 and radon concentration that are not yet understood. It will help to solve the problem of dust which origins from the train operation. The group from Karst Research Institute has an in depth speleological knowledge and long term experiences in cave monitoring. The project leader has fifteen years of experience in modelling karst processes. He has been working on climatic and hydrologic measurements in Postojna cave since seven years. The MEIS group has expertise on micrometeorology of planetary boundary layer in complex terrain settings and pollutant spreading in the atmosphere. They have develope
Significance for science
Beside definitive answers, the project also resulted some partial solutions and opened many challenging questions for further research. Even though the cave environment has been considered stable, we demonstrated high temporal and spatial variability of cave »weather« and assessed important factors and processes governing it. Detailed understanding of all weather patterns observed in the cave remain a challenge for future studies of underground climate. Related to this, an important challenge remains an optimal set up of observation system, which would enable early detection of environmental changes. A better understanding of cave atmosphere resulted from the project, also enables better reconstruction of paleoclimate records from cave sediments and use of cave data for long-term observation of global changes. Fort these, deep understanding of transfer of climatic signal from the surface to the cave is crucial. Furthermore, project opens new possibilities for research of cave biota; caves, as narrow ecological niches, present a great study site for evolutionary biologists; for this reserch a sound understanding of cave climate is crucial. In case of Postojnska jama, present numerical models of ventilation systems cannot capture the complex geometry and numerous processes driving the dynamics of cave atmosphere. Therefore, the main challenge opened in a project, remains an efficient numerical model of cave micrometeorology & microclimate.
Significance for the country
Karst and Postojna cave are part of Slovene identity. Here the first scientific studies on karst phenomena were done more than a century ago. Therefore, it is expected that most innovative karst research still comes from Slovenia. Postojna cave is one of the most famous and visited cave in the world. Its management and care for its environment are a duty of cave manager and of the whole society, which in fact “owns” the cave. The results of this project will enable a better understanding of cave environment and sustainable development of tourism in the cave. At two spots along the tourist trail, an installed equipment is visible. We believe tah more than a disturbance, this instruments show our care for the environment. As a flagship of Slovene tourism, Postojnska jama should also be a flagship of our environmental care. Knowledge and solutions acquired in this project can surely be implemented in show caves worldwide, which all face similar challenges. This also presents a business opportunity for the Slovene companies.
Most important scientific results Annual report 2015, final report
Most important socioeconomically and culturally relevant results Annual report 2015, final report
Views history